1. Field of the Invention
The present invention relates to an absorption cooling device for generating a cooling output by using a refrigerant gas and a lithium bromide.
2. Description of the Prior Art
Referring to FIG. 1, a conventional absorption cooling device is illustrated which generates a cooling output by using a refrigerant gas and a lithium bromide. As shown in FIG. 1, the absorption cooling device includes a generator 1 for separating a refrigerant gas and a concentrated solution from a dilute solution by a heat generated from a burner. The refrigerant gas separated by the generator 1 is condensed by a condenser 3. An evaporator 5 is also provided which serves to evaporate the refrigerant gas condensed in the condenser 3 and thereby generate a cooling output. The absorption cooling device further includes an absorber 7 for changing the refrigerant gas into a dilute solution.
The absorber 7 includes an upper chamber 9 having a space for storing the refrigerant gas fed from the evaporator 5 and the concentrated solution fed from the generator 1. A heat transfer Pipe 11 is connected at one end thereof to the upper chamber 9. The heat transfer pipe 11 defines a passage permitting the refrigerant gas and the concentrated solution to be naturally dropped so that the refrigerant gas is absorbed in the concentrated solution during the dropping. A plurality of heat discharging fins 12 are fixedly mounted to the outer wall surface of the heat transfer pipe 11 and adapted to outwardly discharge heat generated when the refrigerant gas is changed into a dilute solution. To the other end of the heat transfer pipe 11, a lower chamber 10 is connected which has a space for storing the dilute solution produced in the heat transfer pipe 11. A pump f is also provided which generates a power for feeding the dilute solution stored in the lower chamber 10 to the generator 1.
In the conventional absorption cooling device having the above-mentioned construction, the refrigerant gas fed from the evaporator 5 and the concentrated solution fed from the generator 1 are naturally dropped through the heat transfer pipe 11. During the dropping, the refrigerant gas is absorbed in the concentrated solution, thereby forming a dilute solution.
However, the refrigerant gas is in insufficient contact with the concentrated solution in the heat transfer pipe 11 because they are dropped at the same velocity. As a result, the refrigerant gas is insufficiently absorbed in the concentrated solution. This results in a degradation in absorption efficiency of the absorber and thus a degradation in cooling efficiency of the absorption cooling device.
Various types of absorption cooling devices have been proposed for solving the above-mentioned problem.
One example of such conventional absorption cooling devices is disclosed in Japanese Patent Laid-open Publication No. Heisei 3-294768 filed on Apr. 11, 1990 and published on Dec. 25, 1991.
As shown in FIG. 2, the absorption cooling device disclosed in Japanese Patent Laid-open Publication No. Heisei 3-294768 includes an upper chamber 33 having a refrigerant gas inlet 32, a lower chamber 37 having a dilute solution outlet 36, and a heat transfer pipe 40 connected between the upper chamber 33 and the lower chamber 37 and adapted to pass a dilute solution therethrough. A plurality of fins 39 are fixed to the outer surface of the heat transfer pipe 40. The upper chamber 33 is provided at the interior thereof with a concentrated solution supply pipe 41 and an injection nozzle 42 for injecting the concentrated solution into the concentrated solution supply pipe 41.
In the conventional absorption cooling device having the above-mentioned construction, the refrigerant gas fed from an evaporator is absorbed in the concentrated solution injected into the upper chamber 33 by the injection nozzle 42 and thereby changed into a dilute solution which is, in turn, naturally dropped into the heat transfer pipe 40.
In other words, this absorption cooling device is adapted to absorb the refrigerant gas in the concentrated solution in the upper chamber 33 and change it into the dilute solution. In the absorption cooling device, however, even the refrigerant gas portion not absorbed in the concentrated solution is naturally dropped through the heat transfer pipe 40. As a result, the absorption of the refrigerant solution in the concentrated solution is inefficiently achieved. Such an inefficient absorption results in a degradation in absorption efficiency of the absorber and thus a degradation in cooling efficiency of the absorption cooling device.